encryptedioqueue.c

外国开源的硬盘加密软件

								switch (subFragment)
								{
								case 0:
									subFragmentLength = (ULONG) request->EncryptedOffset;
									break;

								case 1:
									subFragmentOffset.QuadPart += request->EncryptedOffset + queue->RemappedAreaOffset;
									subFragmentLength = request->EncryptedLength;
									break;

								case 2:
									subFragmentOffset.QuadPart += request->EncryptedOffset + request->EncryptedLength;
									subFragmentLength = (ULONG) (request->Length - (request->EncryptedOffset + request->EncryptedLength));
									break;
								}

								if (subFragmentLength > 0)
								{
									if (request->Item->Write)
										request->Item->Status = TCWriteDevice (queue->LowerDeviceObject, subFragmentData, subFragmentOffset, subFragmentLength);
									else
										request->Item->Status = TCCachedRead (queue, NULL, subFragmentData, subFragmentOffset, subFragmentLength);

									subFragmentData += subFragmentLength;
								}
							}
						}
						else
						{
							// Remap the fragment
							LARGE_INTEGER remappedOffset;
							remappedOffset.QuadPart = request->Offset.QuadPart + queue->RemappedAreaOffset;

							if (request->Item->Write)
								request->Item->Status = TCWriteDevice (queue->LowerDeviceObject, request->Data, remappedOffset, request->Length);
							else
								request->Item->Status = TCCachedRead (queue, NULL, request->Data, remappedOffset, request->Length);
						}
					}
					else
					{
						if (request->Item->Write)
							request->Item->Status = TCWriteDevice (queue->LowerDeviceObject, request->Data, request->Offset, request->Length);
						else
							request->Item->Status = TCCachedRead (queue, NULL, request->Data, request->Offset, request->Length);
					}
				}
				else
				{
					IO_STATUS_BLOCK ioStatus;

					if (request->Item->Write)
						request->Item->Status = ZwWriteFile (queue->HostFileHandle, NULL, NULL, NULL, &ioStatus, request->Data, request->Length, &request->Offset, NULL);
					else
						request->Item->Status = TCCachedRead (queue, &ioStatus, request->Data, request->Offset, request->Length);

					if (NT_SUCCESS (request->Item->Status) && ioStatus.Information != request->Length)
						request->Item->Status = STATUS_END_OF_FILE;
				}
			}

			if (request->Item->Write)
			{
				queue->ReadAheadBufferValid = FALSE;

				ReleaseFragmentBuffer (queue, request->Data);

				if (request->CompleteOriginalIrp)
				{
					CompleteOriginalIrp (request->Item, request->Item->Status,
						NT_SUCCESS (request->Item->Status) ? request->Item->OriginalLength : 0);
				}
				else
				{
					InterlockedDecrement (&request->Item->OutstandingRequestCount);
					KeSetEvent (&queue->RequestCompletedEvent, IO_DISK_INCREMENT, FALSE);
				}

				ReleasePoolBuffer (queue, request);
			}
			else
			{
				BOOL readAhead = FALSE;

				if (NT_SUCCESS (request->Item->Status))
					memcpy (request->OrigDataBufferFragment, request->Data, request->Length);

				ReleaseFragmentBuffer (queue, request->Data);
				request->Data = request->OrigDataBufferFragment;

				if (request->CompleteOriginalIrp
					&& queue->LastReadLength > 0
					&& NT_SUCCESS (request->Item->Status)
					&& InterlockedExchangeAdd (&queue->IoThreadPendingRequestCount, 0) == 0)
				{
					readAhead = TRUE;
					InterlockedIncrement (&queue->OutstandingIoCount);
				}

				ExInterlockedInsertTailList (&queue->CompletionThreadQueue, &request->CompletionListEntry, &queue->CompletionThreadQueueLock);
				KeSetEvent (&queue->CompletionThreadQueueNotEmptyEvent, IO_DISK_INCREMENT, FALSE);

				if (readAhead)
				{
					queue->ReadAheadBufferValid = FALSE;
					queue->ReadAheadOffset.QuadPart = queue->LastReadOffset.QuadPart + queue->LastReadLength;
					queue->ReadAheadLength = queue->LastReadLength;

#ifdef TC_TRACE_IO_QUEUE
					Dump ("A   %I64d [%I64d] roff=%I64d rlen=%d\n", request->Item->OriginalIrpOffset.QuadPart, GetElapsedTime (&queue->LastPerformanceCounter), queue->ReadAheadOffset, queue->ReadAheadLength);
#endif

					if (queue->ReadAheadOffset.QuadPart + queue->ReadAheadLength <= queue->MaxReadAheadOffset.QuadPart)
					{
						if (queue->IsFilterDevice)
						{
							queue->ReadAheadBufferValid = NT_SUCCESS (TCReadDevice (queue->LowerDeviceObject, queue->ReadAheadBuffer, queue->ReadAheadOffset, queue->ReadAheadLength));
						}
						else
						{
							IO_STATUS_BLOCK ioStatus;
							queue->ReadAheadBufferValid = NT_SUCCESS (ZwReadFile (queue->HostFileHandle, NULL, NULL, NULL, &ioStatus, queue->ReadAheadBuffer, queue->ReadAheadLength, &queue->ReadAheadOffset, NULL));
							queue->ReadAheadLength = (ULONG) ioStatus.Information;
						}
					}

					DecrementOutstandingIoCount (queue);
				}
			}
		}
	}

	PsTerminateSystemThread (STATUS_SUCCESS);
}


static VOID MainThreadProc (PVOID threadArg)
{
	EncryptedIoQueue *queue = (EncryptedIoQueue *) threadArg;
	PLIST_ENTRY listEntry;
	EncryptedIoQueueItem *item;

	LARGE_INTEGER fragmentOffset;
	ULONG dataRemaining;
	PUCHAR activeFragmentBuffer = queue->FragmentBufferA;
	PUCHAR dataBuffer;
	EncryptedIoRequest *request;
	uint64 intersectStart;
	uint32 intersectLength;

	int64 mdlWaitTime;
	LARGE_INTEGER mdlWaitPerfCounter;

	if (IsEncryptionThreadPoolRunning())
		KeSetPriorityThread (KeGetCurrentThread(), LOW_REALTIME_PRIORITY);

	while (!queue->ThreadExitRequested)
	{
		if (!NT_SUCCESS (KeWaitForSingleObject (&queue->MainThreadQueueNotEmptyEvent, Executive, KernelMode, FALSE, NULL)))
			continue;

		while ((listEntry = ExInterlockedRemoveHeadList (&queue->MainThreadQueue, &queue->MainThreadQueueLock)))
		{
			PIRP irp = CONTAINING_RECORD (listEntry, IRP, Tail.Overlay.ListEntry);
			PIO_STACK_LOCATION irpSp = IoGetCurrentIrpStackLocation (irp);
			
			if (queue->Suspended)
				KeWaitForSingleObject (&queue->QueueResumedEvent, Executive, KernelMode, FALSE, NULL);

			item = GetPoolBuffer (queue, sizeof (EncryptedIoQueueItem));
			if (!item)
			{
				EncryptedIoQueueItem stackItem;
				stackItem.Queue = queue;
				stackItem.OriginalIrp = irp;
				stackItem.Status = STATUS_INSUFFICIENT_RESOURCES;

				TCCompleteDiskIrp (irp, STATUS_INSUFFICIENT_RESOURCES, 0);
				OnItemCompleted (&stackItem, FALSE);
				continue;
			}

			item->Queue = queue;
			item->OriginalIrp = irp;
			item->OutstandingRequestCount = 0;
			item->Status = STATUS_SUCCESS;

			IoSetCancelRoutine (irp, NULL);
			if (irp->Cancel)
			{
				CompleteOriginalIrp (item, STATUS_CANCELLED, 0);
				continue;
			}

			switch (irpSp->MajorFunction)
			{
			case IRP_MJ_READ:
				item->Write = FALSE;
				item->OriginalOffset = irpSp->Parameters.Read.ByteOffset;
				item->OriginalLength = irpSp->Parameters.Read.Length;
				break;

			case IRP_MJ_WRITE:
				item->Write = TRUE;
				item->OriginalOffset = irpSp->Parameters.Write.ByteOffset;
				item->OriginalLength = irpSp->Parameters.Write.Length;
				break;

			default:
				CompleteOriginalIrp (item, STATUS_INVALID_PARAMETER, 0);
				continue;
			}

#ifdef TC_TRACE_IO_QUEUE
			item->OriginalIrpOffset = item->OriginalOffset;
#endif

			// Handle misaligned read operations to work around a bug in Windows System Assessment Tool which does not follow FILE_FLAG_NO_BUFFERING requirements when benchmarking disk devices
			if (queue->IsFilterDevice
				&& !item->Write
				&& item->OriginalLength > 0
				&& (item->OriginalLength & (ENCRYPTION_DATA_UNIT_SIZE - 1)) == 0
				&& (item->OriginalOffset.QuadPart & (ENCRYPTION_DATA_UNIT_SIZE - 1)) != 0)
			{
				byte *buffer;
				ULONG alignedLength = item->OriginalLength + ENCRYPTION_DATA_UNIT_SIZE;
				LARGE_INTEGER alignedOffset;
				alignedOffset.QuadPart = item->OriginalOffset.QuadPart & ~((LONGLONG) ENCRYPTION_DATA_UNIT_SIZE - 1);

				buffer = TCalloc (alignedLength);
				if (!buffer)
				{
					CompleteOriginalIrp (item, STATUS_INSUFFICIENT_RESOURCES, 0);
					continue;
				}

				item->Status = TCReadDevice (queue->LowerDeviceObject, buffer, alignedOffset, alignedLength);

				if (NT_SUCCESS (item->Status))
				{
					UINT64_STRUCT dataUnit;

					dataBuffer = (PUCHAR) MmGetSystemAddressForMdlSafe (irp->MdlAddress, HighPagePriority);
					if (!dataBuffer)
					{
						TCfree (buffer);
						CompleteOriginalIrp (item, STATUS_INSUFFICIENT_RESOURCES, 0);
						continue;
					}

					if (queue->EncryptedAreaStart != -1 && queue->EncryptedAreaEnd != -1)
					{
						GetIntersection (alignedOffset.QuadPart, alignedLength, queue->EncryptedAreaStart, queue->EncryptedAreaEnd, &intersectStart, &intersectLength);
						if (intersectLength > 0)
						{
							dataUnit.Value = intersectStart / ENCRYPTION_DATA_UNIT_SIZE;
							DecryptDataUnits (buffer + (intersectStart - alignedOffset.QuadPart), &dataUnit, intersectLength / ENCRYPTION_DATA_UNIT_SIZE, queue->CryptoInfo);
						}
					}

					memcpy (dataBuffer, buffer + (item->OriginalOffset.LowPart & (ENCRYPTION_DATA_UNIT_SIZE - 1)), item->OriginalLength);
				}

				TCfree (buffer);
				CompleteOriginalIrp (item, item->Status, NT_SUCCESS (item->Status) ? item->OriginalLength : 0);
				continue;
			}

			// Validate offset and length
			if (item->OriginalLength == 0
				|| (item->OriginalLength & (ENCRYPTION_DATA_UNIT_SIZE - 1)) != 0
				|| (item->OriginalOffset.QuadPart & (ENCRYPTION_DATA_UNIT_SIZE - 1)) != 0
				|| (!queue->IsFilterDevice && item->OriginalOffset.QuadPart + item->OriginalLength > queue->VirtualDeviceLength))
			{
				CompleteOriginalIrp (item, STATUS_INVALID_PARAMETER, 0);
				continue;
			}

#ifdef TC_TRACE_IO_QUEUE
			Dump ("Q  %I64d [%I64d] %c len=%d\n", item->OriginalOffset.QuadPart, GetElapsedTime (&queue->LastPerformanceCounter), item->Write ? 'W' : 'R', item->OriginalLength);
#endif

			if (!queue->IsFilterDevice)
			{
				// Adjust the offset for host file or device
				if (queue->CryptoInfo->hiddenVolume)
					item->OriginalOffset.QuadPart += queue->CryptoInfo->hiddenVolumeOffset;
				else
					item->OriginalOffset.QuadPart += queue->CryptoInfo->volDataAreaOffset; 

				// Hidden volume protection
				if (item->Write && queue->CryptoInfo->bProtectHiddenVolume)
				{
					// If there has already been a write operation denied in order to protect the
					// hidden volume (since the volume mount time)
					if (queue->CryptoInfo->bHiddenVolProtectionAction)	
					{
						// Do not allow writing to this volume anymore. This is to fake a complete volume
						// or system failure (otherwise certain kinds of inconsistency within the file
						// system could indicate that this volume has used hidden volume protection).
						CompleteOriginalIrp (item, STATUS_INVALID_PARAMETER, 0);
						continue;
					}

					// Verify that no byte is going to be written to the hidden volume area
					if (RegionsOverlap ((unsigned __int64) item->OriginalOffset.QuadPart,
						(unsigned __int64) item->OriginalOffset.QuadPart + item->OriginalLength - 1,
						queue->CryptoInfo->hiddenVolumeOffset,
						(unsigned __int64) queue->CryptoInfo->hiddenVolumeOffset + queue->CryptoInfo->hiddenVolumeProtectedSize - 1))
					{
						Dump ("Hidden volume protection triggered: write %I64d-%I64d (protected %I64d-%I64d)\n", item->OriginalOffset.QuadPart, item->OriginalOffset.QuadPart + item->OriginalLength - 1, queue->CryptoInfo->hiddenVolumeOffset, queue->CryptoInfo->hiddenVolumeOffset + queue->CryptoInfo->hiddenVolumeProtectedSize - 1);
						queue->CryptoInfo->bHiddenVolProtectionAction = TRUE;

						// Deny this write operation to prevent the hidden volume from being overwritten
						CompleteOriginalIrp (item, STATUS_INVALID_PARAMETER, 0);
						continue;
					}
				}
			}
			else if (item->Write && IsHiddenSystemRunning()
				&& (RegionsOverlap (item->OriginalOffset.QuadPart, item->OriginalOffset.QuadPart + item->OriginalLength - 1, SECTOR_SIZE, TC_BOOT_LOADER_AREA_SECTOR_COUNT * SECTOR_SIZE - 1)
				 || RegionsOverlap (item->OriginalOffset.QuadPart, item->OriginalOffset.QuadPart + item->OriginalLength - 1, GetBootDriveLength(), _I64_MAX)))
			{
				Dump ("Preventing write to boot loader or host protected area\n");
				CompleteOriginalIrp (item, STATUS_MEDIA_WRITE_PROTECTED, 0);
				continue;
			}

			// Original IRP data buffer
			mdlWaitTime = 0;
			mdlWaitPerfCounter.QuadPart = 0;
			while (TRUE)
			{
				dataBuffer = (PUCHAR) MmGetSystemAddressForMdlSafe (irp->MdlAddress, HighPagePriority);

				if (dataBuffer || mdlWaitTime >= TC_ENC_IO_QUEUE_MEM_ALLOC_TIMEOUT)
					break;

				if (mdlWaitPerfCounter.QuadPart == 0)
					GetElapsedTimeInit (&mdlWaitPerfCounter);

				TCSleep (TC_ENC_IO_QUEUE_MEM_ALLOC_RETRY_DELAY);
				mdlWaitTime += GetElapsedTime (&mdlWaitPerfCounter) / 1000;
			}

			if (dataBuffer == NULL)
			{
				CompleteOriginalIrp (item, STATUS_INSUFFICIENT_RESOURCES, 0);
				continue;
			}